Best dwarf apple trees for Chicago area

I need your help please! I would  love to add 2 dwarf apple trees to our community garden in the northwest suburbs of Chicago. Please advise me on what types are best. It would be great to have one early variety as that is when we have the most volunteers. I know we eventually need to prune when dormant. Are there varieties that don’t need to be sprayed? I would love to buy them locally.

I am thrilled with my Williams Pride apple, which is an early type. It is one of a group from a breeding partnership between Purdue, Rutgers and the University of Illinois that are all extremely resistant to the major diseases—scab, rust, fireblight, and mildew. My tree is very fast-growing and vigorous with a beautiful open form that has required almost no pruning. It flowered a little in its second year, and in year three right now it is flowering heavily and I expect to taste the fruit, which is supposed to be one of the best-tasting early apples.

Other PRI apple varieties include Enterprise, Pristine, and Priscilla. All of these should be largely no-spray.

I would suggest Liberty as a low maintenance apple and Cox's Orange Pippin as an apple with superior taste. They both ripen in September however. They bloom early and early/mid. Cox is known as a precocious tree and Stark lists both as taking 2-5 years to begin apple production. For an early apple none may ripen earlier than Yellow Transparent a yellow sauce apple that ripens in the 3rd week of July. Yellow Transparent only bears apples every other year and when they ripen every apple seems to fall to the ground the same night. Zestar is an Early-mid August ripening apple that blooms early and has a "Sweet and tangy" taste.
Are there any other apple or crab apple trees in the near neighborhood to serve as pollination partners? Otherwise your two apple varieties need to ripen at the same time.
Seems to me what you need are 2 apples that flower late, one that ripens early and both grow well under organic methods.
I used Stark Bros as a source of info on all the apples so that all the info particularly dates come from the same source. None of the above apples are still in stock from them.